SESSION TITLE: Sleep Disorders Posters I: Diagnosis
SESSION TYPE: Original Investigation Poster
PRESENTED ON: Wednesday, October 28, 2015 at 01:30 PM - 02:30 PM
PURPOSE: Hunter-Cheyne-Stokes breathing with central sleep apnea (CSA) commonly occurs in patients with heart failure (HF). Previous research has shown conversion of predominantly obstructive sleep apnea to CSA throughout the night. We hypothesized that the density and duration of CSA events would increase overnight in patients with HF with predominately CSA.
METHODS: As part of a worldwide Pilot Study (Chronic Evaluation of the remedē® System), patients with known risk factors for sleep disordered breathing underwent full night attended polysomnography (PSG) scored according to AASM 2007 guidelines. HF patients (LVEF<40) with CSA were included (n=41 of the 60 studies completed). Total sleep time (TST) for each participant was divided into 8 equal segments and all events were assigned to a particular segment based on the time of occurrence. Segment event counts were normalized to an index based on sleep segment duration. REM sleep was excluded due to a known resolution of CSA during REM sleep. The differences in central apnea index (CAI) and central apnea durations among sleep segments were analyzed using repeated measures ANOVA.
RESULTS: Participants were 65.7±1.5 (Mean ± SE) years of age with a baseline apnea hypopnea index of 51.0±2.2 per hour and central apnea index of 28.0±2.5 per hour of sleep. Obstructive apnea index was 3.5±0.7 per hour of sleep. The average TST was 4.7±1.35 hours. The average segment duration was 35.1±1.19 minutes. CAI increased during the later segments of sleep (p=0.0011) with a minimum CAI (20.8±3.4 events/hour) in the 2nd segment and the maximum CAI (36.8±3.7 events/hour) during the 8th segment. Average duration of central apneas lengthened later in the night (p-value=0.0047). Obstructive and mixed apnea indices did not change significantly throughout the night. Hypopnea index did show a decrease later in the night (p-value= 0.0166) accounting for part of the change in CAI. There were too few obstructive events to analyze the duration of obstructive apneas throughout the night.
CONCLUSIONS: We conclude that in patients with HF and predominantly CSA, non-REM burden of CSA reflected in the number and duration of central apneas worsens throughout the night. Rostral fluid shift has been a known underlying mechanism for conversion from OSA to CSA and may also account for increased overnight burden of CSA in HF.
CLINICAL IMPLICATIONS: CSA burden increases throughout the night. It is therefore important that therapies maintain efficacy throughout the night.
DISCLOSURE: Shahrokh Javaheri: Consultant fee, speaker bureau, advisory committee, etc.: Respicardia Inc. Nathan Cameron: Employee: Respicardia Inc. William Abraham: Consultant fee, speaker bureau, advisory committee, etc.: Respicardia Inc. Robin Germany: Employee: Respicardia Inc. Piotr Ponikowski: Consultant fee, speaker bureau, advisory committee, etc.: Respicardia Inc.
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